1. Field of the Invention
This invention generally relates to network switching devices and more particularly to Fibre Channel switching devices.
2. Description of the Related Art
With client/server applications demanding high bandwidth and low latency input/output (I/O) characteristics for high speed data transmissions, conventional network and channel technologies are confronted with serious limitations. Conventional network technology (e.g., Ethernet- or Token Ring-based systems) provides shared bandwidth access for multiple clients and the ability to handle unpredictable small-packet bursty traffic, but lacks the ability to meet the growing bandwidth requirements of many client/server applications. Conventional channel technology (e.g., telephony) provides high speed data and low latency transfer characteristics, but lacks the ability to provide connectivity among multiple clients with small-packet bursty traffic.
Fibre Channel, an American National Standards Institute (ANSI) standard for high speed fiber optic communication interfaces, offers the joint advantages of both the conventional network and channel technology to a variety of Fibre Channel compliant hardware systems such as personal computers, workstations, mainframes, storage devices and servers. With regard to client/server applications, the use of such Fibre Channel-based systems is proliferating into mass storage, medical and scientific imaging, multimedia communication, transactional processing, distributed computing and distributed database processing applications.
For a source Fibre Channel compliant end-device (Nx_Port), which is attached to a Fibre Channel fabric, to communicate with other Nx-Ports, which are attached to the fabric, the source Nx_Port must log into the fabric as well as register and query the fabric""s Simple Name Server (SNS) for Fibre Channel attributes of other registered Nx_Ports. With regard to logging into the fabric, the source Nx_Port must support the Fabric LOGIN (FLOGI) service. To communicate with the other Nx_Ports, the source Nx_Port must support the destination Port LOGIN (PLOGI) service as well as be able to register and query with the SNS for Fibre Channel parameters.
In conventional systems, the source Nx-Port initiates FLOGI to allow the source Nx_Port to obtain service parameters relating to the fabric. If the source Nx_Port completes FLOGI, the source Nx_Port then registers its Fibre Channel attributes with the SNS, thereby enabling the source Nx_Port to query the SNS for the Fibre Channel attributes of other Nx_Ports. If the source Nx_Port successfully performs FLOGI as well as registers with the SNS, the source Nx_port will be able to initiate PLOGI to communicate with any other registered Nx_Port.
Such robust login and registration functionality, however, does not always exist in Nx_Ports. For example, in some instances, even if the Nx_Port is a public device (e.g., capable of FLOGI), the Nx_Port may not be designed to initiate such operations as SNS query and registration, thereby precluding the source Nx_Port from possessing the capability for communicating with other Nx_Ports. Without SNS registration, other Nx_Ports will not be informed of the existence of the source Nx_Port and will not be able to successfully perform PLOGI with that source Nx_Port. In yet another instance with regard to the arbitrated loop topology, not every NL_Port is a public port, thereby resulting in private NL_Ports unable to perform FLOGI with the fabric or PLOGI with other Nx_Ports. The conventional solution to each of these limitations is for the Fibre Channel fabric system not to support these Nx_Ports.
What is needed is a system and method that concurrently registers multiple end-devices, such as source Nx_Ports, with the fabric without requiring the source end-device to possess the requisite functionality for initiating the login and registration with the fabric.
In accordance with the system and method of the present invention, the limitations of fabric registration by end-devices are resolved by enabling a fabric to concurrently probe multiple end-devices to obtain registration information from the end-devices. By allowing the fabric to directly obtain such registration information, end-devices, which would otherwise be unable to register with the fabric, can now be registered. In addition, by relying upon such a probing system and method, a fabric also can avoid requiring any end-devices from having to initiate login with the fabric.
In accordance with the principles encompassed within the present invention, the system includes a switch port manager module, a probe module and a registration server. The switch port manager module detects the active switch ports coupled to the fabric and initiates the probing of a plurality of end-devices coupled to at least one of these active switch ports. The probe module then responds by allocating probe resources for probing each of the plurality of end-devices coupled to each active switch port. Once the probing resources are allocated, the probe module logs into each end-device and probes each end-device for registration information, such as service parameters and a symbolic name. The switch port manager module then triggers the registration server to register this registration information with the fabric for later retrieval by other registered end-devices.